从服务可观察到的组件捕获错误

Question

In my Angular 2 app, I tried to catch an error on a component level that is thrown from service.

For instance.

class ServiceA
{
  getCustomer()
  {
    this.http.get('/someURL').subscribe(
      (data) => {
        return data;
      },
      (err) => {
        throw err
      }
    )
  }


class ComponentA
{
  constructor(
    private serviceA : ServiceA
  ){}

  ngOnInit()
  {
    try
    {
      let var1;
      var1 = this.serviceA.getCustomer()
    }
    catch(err)
    {
      //How do I trigger this catch to work ?
      console.log(err);
    }

  }
}

What is wrong in my code above ? Why isn't it working ?

Answer 1

You are subscribing in the service itself and not in the component. Also getCustomer() is not returning anything.

Return just the observable from getCustomer() . Map the Response value.

getCustomer()
  {
    return this.http.get('/someURL').map(
      (data) => {
        return data.json();//if response content type is json
      },
      (err) => {
        throw err
      }
    )
  }

Subscribe in component.

  this.serviceA.getCustomer().subscribe(data=>{
    var1=data;
  },err=>{
   console.log(err);//get the error in error handler
  });